Key Items

Key Items are collectible objects that are generally used as to open special doors or solve puzzles, and are generally finite in number. The only exception to this is the Proud Soul, which is rewarded after every mission in Devil May Cry 4, and replaces Red Orbs as the currency used to purchase new abilities. Certain Key Items can also drain the player's health, forcing them to use the item before they expire. It is impossible to keep Key Items in the inventory throughout missions, as they operate as plot items, and while this is still true in Devil May Cry 4, the abilities that the Key Items in that game grant can be used, once obtained, regardless of whether the player still possesses the Key Item or not.

Rusty Key
Rusty Keys are old but functioning keys found throughout Mallet Castle and are used to unlock certain doors. There are three of them in Devil May Cry:
 * 1) The first key is found inside the hand of a seemingly lifeless puppet within the gatekeeper's room and is used to open the door to the hangar.
 * 2) The second key is found embedded in the painting of a Grim Reaper within the library and is used to open the door to the courtyard.
 * 3) The final key is found within a pipe in the waterways and is used to open a door further along them.

Staff of Judgment

 * A mysterious ornamental staff found in Mallet Castle that is required to open the Judge of Death door. It cannot be used as a weapon.

Pride of Lion

 * A somewhat sacred seal that allows passage through the Lion's Door. (Shadow)

Death Sentence & Melancholy Soul

 * The Death Sentence is an extremely decorative sword that is said to be used for rituals, although its only in-game function is to act as a key to retrieve the Melancholy Soul from the Melancholy bust. It cannot be wielded.
 * A strange ornament that is described to look like a soul, although it merely looks like a brownish-reddish ball with speckles. It acts as the key into the Mallet Sewers, although it must be inserted into the door quickly, or else it will lose its power.

Guiding Light

 * A literal key to unlocking the sun door in Mallet Castle that leads to an unholy ritual chamber holding a Divinity Statue. It must be inserted quickly into the sun door however, or it will slowly kill Dante.

Trident

 * A decorative pike that is used as a key to unlocking the iron wrought gate in Mallet Castle. It cannot be used as a weapon.

Sign of Chastity & Chalice

 * A taxidermic organ coated in a strange crystal, it acts as a key to unlocking the safeguard to the Chalice. It most closely resembles a brain.
 * A seemingly sacred goblet that apparently held the blood of important mythological deities.

Staff of Hermes

 * A symbol often used to represent alchemy, it acts as a key to opening two magical mirrors. It cannot be used as a weapon.

Emblem Shield & Pair of Lances

 * A small shield donning the insignia of a skull, it acts as a key to unlocking two doors: one leads to the Pair of Lances, and the other leads to the hidden Fire Arm, Nightmare Beta. The Emblem shield is one of the few key items that can be used more than once.
 * A pair of small, but heavy-looking javelins held by the knight statues on the coliseum double doors which allow passage into the sacrificial grounds. They cannot be wielded as weapons.

Luminite
Luminite is an ordinary Underworld stone that has become fluorescent when brought to the Human World. It can be found during Mission 15: Wheel of Destiny, in a pile of rubble blocking the corridor surrounding the Coliseum, and it must be obtained in order to open the doors of the lower corridors containing the Pair of Lances and the Nightmare-β.

Wheel of Destiny
A round, metal plate with engraving that represents destiny. Required to re-lower the drawbridge of Mallet Castle.

Quicksilver
A clear, crystal ball filled with mercury, or quicksilver. Needed to unlock the door to the Castellan's Throne Room.

Philosopher's Stone
A mysterious geometric stone covered with alchemy-related engravings. Needed to open the Mouth of the Underworld.

Astronomical Board
The Astronomical Board is found within a red pillar in the Astral Chamber. It is an astrological device powered by time which displays the endless void, and is used to deactivate the gates set along the stairs in the Chamber of Echoes.

Orihalcon
Orihalcon is a mysterious red stone which can be used as an energy source.

Proud Soul


The Proud Soul is obtained after completing a mission, and the amount of Proud Souls obtained is dependent on the rank received in the mission. It is a manifest soul that is filled with pride due to its noble blood, and is used to purchase new abilities from a Divinity Statue.

Wing Talisman


The Wing Talisman (羽のタリスマン) is found within a red pillar in the Spiral Well. It is a crystal talisman containing an angel's wing that can be used to activate certain equipment which will propel Nero or Dante upwards if stepped upon. These pads are usually red, though there are some blue ones that effect a much greater response. There is also an elevator within Experiment Disposal which requires the Wing Talisman to be placed inside of it to move, and Nero does so while searching the H.Q. for Kyrie. Dante later retrieves the talisman.

Key of Cronus


The Key of Cronus (クロノスの鍵) is found within a violet pillar in the Key Chamber. It is a magical key intended for use with the Chrono Slicers, time suspension devices being developed by the Order's technology department. Most of them are incomplete and will only remain active for a short time. However, there is one Chrono Slicer within the Security Corridor which functions indefinitely if the key is left inside, and Nero does so while searching the H.Q. for Kyrie. Dante later retrieves the key, and uses it to wreck some of the machines in the Security Corridor.

Background
A Vajra is a short metal weapon with a name meaning both "thunderbolt" and "diamond", said to have the nature of a diamond (it can cut any substance but not be cut itself) and the nature of the thunderbolt (irresistible force). It was a spiritual implement used symbolically in Indian religions. In Hinduism, it was considered the weapon of Indra, the god of weather.

Orihalcon is a valuable red metal of Greek legend which was said to cover the Temple to Poseidon and Cleito on Atlantis and the vessels within the Temple of Solomon. It was said to be an alloy of copper, usually with gold.

The Philosopher's Stone was a mythical stone said to have the power to change any metal to gold, and in some legends, produced the Elixir of Life, which granted immortality to the drinker.

Crystal skulls are models of the human skull carved from clear or milky quartz. The life-size specimens are often claimed to be pre-Columbian Mesoamerican artifacts which radiate psychic energy, but mainstream scientific opinion holds that they are forgeries manufactured in Europe.

The Sirens were bird-women who lured mariners into shipwrecking with their enchanting singing. Their name is similar to foreign names for the Mermaid, a similar creature that was a fish-woman hybrid.

Ambrosia is a fragrant food or drink of the gods in Greek mythology, and was depicted as conferring ageless immortality upon consumption, though it was poisonous to mortals. It is thought to be either a type of honey or a hallucinogenic fungi such as Amanita muscaria.

Samsara is the cycle of reincarnation or rebirth due to karma in religions such as Hinduism and Buddhism. It is considered a state of suffering that can only be ended by enlightenment or pious deeds.

Cronus is the Roman god of the harvest, but in this case is a mis-romanization of Chronos, the personification of time in Greek mythology. Cronus and Chronos are often mistakenly conflated.